Author Topic: Renault engine - ignition timing, fuel & oil.  (Read 2408 times)

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Offline StephenH

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Renault engine - ignition timing, fuel & oil.
« on: Thursday,September 19, 2013, 12:33:19 AM »
Just finished a discussion with the local Alpine Renault guru after he has given my S2 the once over.
Recently purchased, I haven't been completely happy with the engine performance (although it isn't slow).

Nothing low down and bad mannered, which I had put down to having a giant cam and 45mm Webers.
As the detailed knowledge of the engine build and spec was light on I though running it past 'the man' was a reasonable idea.

Summary, found the ignition timing was fairly retarded compared to what he thought it could tolerate and basically not much else.
Advanced the ignition and (he tells me) it is a lot more responsive everywhere.

Before I disclose what the timing is, anyone got comments about what they think a warm R16 crossflow should run as static and maybe maximum advance?
Fuel is 98octane RON.
I know this is a 'how long is a piece of string' question but have to start somewhere.

Other question is in regard to recommended oil, this motor is still fairly tight, think I will drop the oil shortly and replace with some straight mineral oil, maybe 20W60  (no cold weather here).
Might swap to a synthetic later but given it is an old design suspect it will need to remain a bit heavier to keep up the pressure.


Stephen
54/1690 1969 S2

Offline buzzer

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Re: Renault engine - ignition timing, fuel & oil.
« Reply #1 on: Thursday,September 19, 2013, 05:30:24 AM »
On the ignition timing issue, there are some good calculators on line to work out what it should be based on capacity, chamber shape revs etc. I did have an old dos programme which I can,t find that did a good job on my crossflow ford lump. Ultimately a final tune on rolling road might be needed especially to get the advance profile correct. Are you operating a vacuum advance system ?

On the oil front a good 20/50 10/50, not sure you would really need a20/60, but what do Renault boys recommend..  If you are running in I would use conventional quality mineral based oil then change to something like mobile 1 after run in. Some engines do not like synthetic oils to run in so I have been told.

Dave
Dave,

Other cars. Westfield SEiW. BMW E90 Alpina D3. BMW 325 E30 convertible and Range Rover CSK

Offline LotusJoe

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Re: Renault engine - ignition timing, fuel & oil.
« Reply #2 on: Thursday,September 19, 2013, 10:44:20 AM »
I would guess 10 to 12 degrees initial timing with somewhere in the neighborhood of 27 to 30 degrees at full advance around 3,000 RPMs.  :confused:
Joe Irwin
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Offline StephenH

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Re: Renault engine - ignition timing, fuel & oil.
« Reply #3 on: Thursday,September 19, 2013, 07:25:47 PM »
Picked up the car this morning and it is a happier vehicle, not as flat 'off the cam'.
Aside from the retarded ignition timing the thermostat was checked and found to be dodgy so replaced as well.

Joe you are spot on, 10 degrees initial timing with 30 degrees at full advance .
The guru has suggested up to another 5deg might be acceptable, will look at that on a hot day and when I can do some repeatable load tests, or leave for a dyno run.

FYI: Cylinder pressures around 200lbs.
Stephen
54/1690 1969 S2

Offline Mecky

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Re: Renault engine - ignition timing, fuel & oil.
« Reply #4 on: Thursday,October 03, 2013, 07:06:31 AM »
Hi,

28 degrees at full advance is recommended by our local Renault Alpine guru.

Regards

Stefan